Automatic piston loader



Jan. 26, 1960 Filed Feb. 20, 1957 c. F. JONES 2,922Q222 AUTOMATIC PISTON LOADER 8 Sheets-Sheet 1 F f 64 22 I 52 Q Q Q 12? l6\ M Q 226 61 22 12 Q Q 4 INVENTOR. Crgywll/nea wan/ 40444 C. F. JONES AUTOMATIC PISTON LOADER Jan. 26, 1960 8 Sheets-Sheet 2 Filed Feb. 20. 1957 INVENTOR. Ceryu/Ffi 7285, 24 m. 0 9

Jan. 26, 1960 c. F. JONES AUTOMATIC PISTON LOADER 8 Sheets-Sheet 3 Filed Feb. 20. 1957 INVENTOR. Cryzuj' 07266,

Jan. 26, 1960 c. F. JONES AUTOMATIC .PISTON LOADER 8 Sheets-Sheet 4 Filed Feb. 20. 1957 INVENTOR. Cergyzz/ZZ/[mea BY MJ 7" Jan. 26,1960 0. F. JONES 2,922,222

AUTOMATIC PISTON LOADER Filed Feb. 20, 1957 8 Sheets-Sheet 6 Jan. 26, 1960 Q R JQNES 2,922,222

AUTOMATIC PISTON LOADER Filed Feb. 20, 1957 8 Sheets-Sheet 7 2 INVENTOR. N CerywJI/b nee, BY 5 aw Jan. 26, 1960 c. F. JONES AUTOMATIC PISTON LOADER 8 Sheets-Sheet 8 Filed Feb. 20. 1957 INVENTOR. Ce-/' zywj1f0ne5 United States 2,922,222 AUTOMATIC PISTON LOADER Cernyw Fredrick Jones, Economy, lnd., assignor to Perfect Circle Corporation, Hagerstown, Ind, a corporation of Indiana Application February 20, 1957,. Serial No. 641,395

22 Claims. (Cl. 29-211) machine which automatically loads sets of piston ring elements on pistons.

A further object is to provide a novel piston loading machine which automatically picks up a full set of piston ring elements, loads them on the piston, and resets itself for a succeeding loading operation.

Other objects and advantages of the machine will become apparent from the following description taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a reduced scale perspective view of a preferred form of amachine embodying the features of this invention.

Fig. 2 is another perspective view of the machine illustrated in Fig. l and showing another side of the machine.

Fig. 3 is a front elevation View of the machine shown in Fig. 1.

Fig. 4 is a fragmentary top plan view of part of the machine shown in Fig. 1, showing the structure of the loading portion thereof.

Fig. Sis a sectional view of the part of the machine as seen along the line 5-5 of Fig. 4.

Fig. 6 is a sectional view as seen along the line 6-6 of Fig. 4.

Fig. 7 is an enlarged fragmentary sectional view of a part of the machine and taken on the line 7-7 of Fig. 6.

Fig. 8 is an enlarged fragmentary sectional view, taken along the line 8-8 of Fig. 3. I

Fig. 9 is a fragmentary perspective view on an enlarged scale of a portion of one of the jaws used in the machine.

Fig. 10 is a fragmentary perspective view showing, by way of example, a typical set of piston ring elements that may be loaded on a piston by the machine.

Fig. 11 is a side elevation view of a portion of a piston with the rings shown in Fig. 9 mounted thereon, the rings being shown in section.

The pistons of virtually all internal combustion engines are equipped with one or more piston rings. Although there are many types of rings used, notwithstanding the differences that may exist, practically every ring is provided with a gap so that the ring may be circumferentially spread for loading it on a piston, that is, spread sufiiciently for the piston to pass through the ring during loading. Once the ring is in position relative to its groove on a piston, it is allowed to snap into place therein. In some instances, of course, the gap in the ring also provides for expansion and contraction of the ring due to the condition of the cylinder. Some forms of rings are sufficiently flexible so that they may be spread readily by hand and placed on the piston. On the other hand, some rings are so stiff that they can not be expanded easily by hand to the extent necessary to allow them to be atenr loaded on the piston. An example-of such a ring is an ordinary compression ring, which is commonly made of generally rectangular radial cross-section." The stiffness of a ring of this type is usually such that it cannot be spread manually, and, therefore, for loading it some auxiliary tool, fixture, or the like .is required to aid in placing it on the piston. A ring of this type, when spread, does not need to be supported throughout its entire circumference, but merely requires support adjacent the gap, since there is no great distortion of the ring-outof its normal plane as it is spread.

In addition to compression rings, the pistons of many engines are provided also with oil rings. Several types of oil rings currently in use are assemblies of .a number of ring elements, such as one or more thin steel rails with a spacer or positioning memberin the ring groove ofthe piston to hold the rail or rails inthe desired position. The rails of this type of ring are usually made from a flat strip of metal bent edgewise into annular form. ,As a result of this method of forming and, also, because the 'rail is relativelythin compared to its radial width, the

rail may tend to distort out of its normal plane when circumferentially spread. Such distortion would prevent the rail from properly seating in its piston groove on the spacer or positioning means therein unless supported in a manner to prevent such distortion.

A typical set of piston rings, the loading of which presents problems involving the factors above mentioned, is illustrated in Figs. 10 and 11. It should be noted, however, that these rings are shown as an illustrative example only, and that machines embracing the features of this invention are not to be limited to the particular form or number of rings shown herein. By various modifications, such machines are capable of loading practically any type of piston ring without departing from the, scope of this invention.

For the particular piston shown fragmentarily in Fig. 11, two compression rings 10 are employed. These compression rings, as mentioned above, are made of. cast iron and are shown as having a rectangular cross-section. The compression rings are placed in the upper grooves of the piston, and thus, the rings 10, areshown mounted in grooves 11 and 12.

The oil ring, shown in this instance, comprises a combined spacer-expander member 13 and a pair of rails 14. The combined spacer-expander member 13is shown .as being of the circumferentially expansible type and .is highly flexible so that it may be readily placed in agroove by hand. The rails 14, on the other hand, are quite stiff and, because they are relatively thin compared to their radial width and because of the way they are made, they easily become distored out of their normal plane when circumferentially spread. The elements of the oil ring are mounted in the lowermost groove 16 of the piston, the expander member 13 being placed in the groove first to hold the rails 14 adjacent opposite sides of the groove .while tending toforce them radially outwardly.

From the foregoing description of the characteristics of two specific types of rings, it will be readily appreciated that to properly mount the different types of rings on pistons usually requires the use of jigs, fixtures,;tools or other appropriate aids. Heretofore, a number of such jigs, fixtures, and tools have been provided which to some extent have successfully solved many of the problems involved. Virtually all of the devices heretofore provided, however, have required a substantial amount 'of manual manipulation during the process of loading the rings on -a piston. Also, most of the devices heretofore provided, although they may have improved piston loading techniques, have been directed tothe problem of loading a single ring or a singleset of rings on a piston and for this reason have been inadequate in filling the needs of the mass production engine manufacturer who desires a Single machine that will quickly, automatically and repeatedly load sets of rings on pistons, as outlined in the foregoing objects. j

Broadly speaking, this invention accomplishes its objects by providing a piston loading machine which includes holding means adapted to hold a set of rings, to circumferentially spread or expand the set in condition to be received over the end of a piston, and to automatically release the rings as soon as the piston is brought into the ring receiving position, so that the former will automatically snap into place in the grooves on the latter. The machine also includes means for transferring rings automatically and by sets, from supplies thereof to the holding means as a consequence of loading a preceding set of rings on a piston, and storage units for holding large quantities of the various ring elements and for conveying them to the transfer means as needed are provided. The operation of the above generally described mechanisms is coordinated by control means of such character that each mechanism functions automatically in a predetermined sequence of operation triggered by the insertion of the piston into the machineand the removal thereof after the piston has been loaded.

A preferred form of the machine is illustrated in Figs. 1 through 8 inclusive. The components of the machine are mounted on a rather massive base 17, with the ring loading components, shown generally at 18 in Figs. 1 and 2, being mounted generally on one portion of the base while many of the control components are collectively arranged on a control panel portion, shown generally at 19 and located at one side of the piston loading portion. The piston loading portion 18 includes structure, shown generally at' 21, that is carried at the front of the base 17 in a generally upright but slightly tilted position. The structure 21 is, in effect, the focal point of the machine since it is within this structure that the various piston ring elements are collected and arranged in predetermined relationship with respect to each other in condition to be mounted on pistons. In the instant machine, the greater portion of the structure 21 is supported by a generally rectangular platelike member 22 mounted on the front of the base. The member '22 is generally upright but slopes downwardly forwardly from top to bottom. The piston loading portion of the machine illustrated is generally symmetrical with respect to a vertical plane through the center of the loading components.

elements in the grooves on a piston, it is customary to circumferentially expand or spread the ring sufficiently to be received over the head or grooved end of the piston. The rings are then held in expanded condition until brought into radial alignment with their respective grooves on the piston, the rings are then released and thus allowed to snap into place. To the end of accomplishing these functions automatically, the instant machine is provided with means that collects, circumferentially spreads, and holds a set of piston ring elements in condition for mounting on a piston and that automatically releases the elements when the piston is brought into loading relation therewith.

More specifically this means includes a pair of movable jaws 23 and 24, an expanding plunger 26 and a spreading vane 27, all of which cooperated to accomplish the foregoing functions. The primary function of the jaws 23 and 24 is to collect a set of piston ring elements, to hold the elements in axially spaced relation relative to each other and to prevent distortion of the elements, as they are spread. The jaws 23 and 24 are arm-like members pivotally mounted in side-by-side relation on the portion 22. Thus, pivot pins 28 and 29 extend through the lower adjacent ends of the jaws 23 and 24, pivotally securing them to the portion 22. At their free ends, the jaws 23 and 24 are formed to provide upper concave portions 30, the radius of curvature thereof being approximately equal to the radius of a piston, the two portions 30 being complementary to define, when the jaws are closed, an opening.

therebetween that is generally circular in cross-section. These portions of the jaws 23 and 24 are the ring holding portions thereof and are formed to hold the ring elements in predetermined spaced relation with respect to each other as hereinafter described. To accommodate the spreading vane 27, also described hereinafter, the jaws are formed so that, even when they are fully closed, a gap 31 exists between the adjacent upper ends thereof. The jaws 23 and 24 are provided at their lower ends with lateral extensions 32 and 33 respectively, that move therewith and close a pair of switches 34 and 36 respectively when the jaws are fully closed.

To enable the jaws to hold the ring elements in predetermined spaced relation with respect to each other and, in order that the ring elements may be transferred to the jaws by mechanical means rather than by hand, the portions 30 are provided with ring carrying slots. The number of slots therein is determined by the number of piston ring elements to be loaded as a set by the machine. In the present instance the machine is designed to load a set of piston ring elements similar to that illustrated in Figs. 10 and 11, that is, a pair of compression rings 10 and a pair of oil ring rails 14. For this reason the jaws herein shown are provided with four such slots, 37, 38, 39 and 41, shown in Figs. 8 and 9. As shown in Fig. 3, in the upper half of the portions 30, the slots extend radially completely through the jaws with respect to the curved edges so that the piston ring elements may be transferred by mechanical means edgewise and downwardly into the jaws. In the lower half of the portion 30, the slots open only radially inwardly, defining a ring-shaped groove for supporting the ring elements as they are deposited in the jaws through the open upper half thereof. Dimensionally speaking, the slots are sufficiently extensive radially to allow the piston ring elements to spread or expand edgewise therein, but the width of the slots is only slightly greater than the thickness of the respective ring elements to be accommodated thereby and, thus, the side walls defining the slots confine the piston ring elements to predetermined planes. In the present instance slots 37 and 38 carry the oil ring rails while slots 41 and 39 carry the compression rings, and thus, the width of slots 37 and 38 are each only slightly wider than the thickness of the rails while the slots 39 and 41 are only slightly wider than the thickness of the compression rings. Thus, the jaws 23 and 24 are adapted to support the piston ring elements so that they may be circumferentially expanded, while holding them against being warped, dished or otherwise distorted. The spacing of the slots with respect to each other in the jaws 23 and 24 corresponds to the spacing of their respective piston ring elements when properly mounted on a piston. In other words, upon a piston being properly positioned in loading relation with respect to the jaws 23 and 24, the slots will be in radial alignment with the respective grooves of the piston that the ring elements will occupy. The jaws may be conveniently formed with the, slots herein described by fabricating them of appropriately shaped and dimensioned plates or laminations, as shown in Fig. 9.

As previously indicated, the jaws 23 and 24 are movable, and in this instance occupy three distinct positions, namely, a closed position, an intermediate position and an open position. The closed position is the ring receiving position, and in this position the greatest disstance between the arcuate edges of the portions 30 is somewhat less than the diameter of the piston ring elements in relaxed condition. The intermediate position is the piston loading position, and in this position the distance between the arcuate edges of the portions 30 is slightly greater than the outer diameter of the piston but is less than the outer diameter of the piston ring elements after they have been snapped into place on a piston. The open position is the assembly released position, and in this position the greatest distance between o the arcuate edges of the portions "30 is greater than the outer d1ameter of the piston ring elements when mounted on the piston, so that the piston with the rings mounted thereon may be withdrawn from the machine.

Movement of the jaws between these positions is effected by hydraulic cylinders acting through appropriate linkages. Thus, for actuating the jaw 24-, a fluid cylinder 42 is mounted on the base 17 to the left of the machine in a generally vertical position, as shown in Fig. 3. The cylinder 42 has its piston rod connected by a link 43 to one arm 44 of a bell crank 46. The other arm 47 of the bell crank 46 is pivotally connected to a rod 48 which in turn is pivotally connected to the jaw 24 at a point intermediate its portion 30 and the pivot pin 29. The length of rod 43 is adjustable for adjustment of the degree of closing of the jaw 24. Also, the limits of movement of the jaw 24 about the pivot 29 may be adjusted. This is accomplished by adjusting a stop mechanism 49, carried on the upper end of the piston rod 51, that limits the length of the stroke of the piston in the cylinder 42. Upon movement of the piston of cylinder 42 to its uppermost position, the jaw 24 is moved to closed position and upon movement of the piston to its lowermost position, the jaw is moved to fully open position.

In order to actuate the jaw 24- from the'fully closed position to the intermediate position, previously described, a secondary fluid cylinder 52 is provided. The cylinder 52 is mounted on an appropriate bracket 53 on the member 22 in spaced relation above the fluid actuated cylinder 42. The piston rod 54 of the cylinder 52 projects downwardly in alignment with the piston rod 51 of cylinder 42. The jaw 24 is actuated from the fully closed to the intermediate position by a force exerted downwardly on the piston rod 51 by the cylinder 52, which is suificient to overcome the upward force exerted by the cylinder 42. To this end, the cylinder 52 is larger in diameter than the cylinder 42, and thus, the piston rod 51 is caused to move downwardly thereby, carrying with it the link 4-3. The extent of downward movement caused by the cylinder 52 is, however, limited by an appropriate adjustable interconnecting mechanism so that the jaw will not be moved to completely open position. That mechanism includes a sleeve-like guide 56, rigidly secured to the bracket 53 so that its bore is in alignment with the piston rods 54 and 51 between the opposing ends thereof. Slidably mounted in the guide 56 between the opposing ends of the rods 54 and 51 is a pusher element 57 for transferring the downward force of the cylinder 52 from the piston rod 54 to the piston rod 51. The extent of downward movement of the pusher element 57 is limited by a pair of stop-nuts 58 that are threaded on the upper-end thereof and abut against the guide 56 when the pusher element 57 has reached its predetermined downward limit of movement.

The jaw 23, being a counter-part of the jaw 24, is actuated by a mechanism similar to that'just described, including a fluid cyilnder 59, a link 61, a bell crank 62, a rod 63, and secondary cylinder 64.

To insure against undue closing of the jaws 23 and 24, an accurately dimensioned abutment block 66 is rigidly mounted on the base between the jaws. The abutment block 66 acts as a stop against which both jaws abut when they are brought to the fully closed position. For control purposes, hereinafter discussed, an auxiliary arm 67 is provided on one of the bell-cranks, in this instance bellcrank 46, which arm is positioned to close a switch 68 when the jaws have been moved to fully opened position.

In order to expand the set of piston ring elements, as mentioned above, the machine is provided with the expanding plunger 26. The plunger 26, in this instance, is an elongated structure carried by the base, and it is longitudinally reciprocable between an extended and a retracted position. In the extended position the structure projects through an opening 71 (see Fig. 6)- in the member 22 so that its forward end, including its expander mechanism, is positioned in the circular opening defined by the jaws 23 and 24 and the piston ring elements carried thereby. In its retracted position, the plunger 26 is positioned so that its forward end is withdrawn rearwardly sufiiciently to permit a piston to be inserted into the opening defined by the jaws, in ring receiving position within the expanded rings.

The expander plunger 26 is most clearly shown in Fig. 6. In this instance the plunger 26 is an elongated assembly including a head portion 72 that is mounted with one end at the opening 71 in the member 22. The head portion 72 is movable along an axis perpendicular to the plane of the member 22 and in alignment with the central axis of rings carried in the jaws 23 and 24 so that the expander mechanism carried on the forward end thereof may be moved into and out of contact with the inner edges of such rings. At its rearward end, the head portion 72 is connected to an elongated connecting rod 73 which is, in turn, connected to a piston rod 74 of a fluid actuated piston in a cylinder 76. The longitudinal axes of the cylinder 76, the rod 74, the rod 73 and the head portion 72 are in substantial alignment with the axis of the rings and are perpendicular to the plane of member 22.

The expander plunger 26 is carried by structural portions of the base, including the member 22 and other structure located rearwardly therefrom and shown generally at 77. The structure shown at 77 is provided with a guide portion 78 having a suitable bushing 79 thatmaintains the rod 73 in axial alignment as the latter is moved axially therethrough. The cylinder 76 is mounted in fixed relation on the rear end of the guide portion 73, its piston rod 74 being in alignment with and connected to the rod 73.

In the instant case, the piston rod 74 extends rearwardly from the cylinder 76, as well as forwardly for connection with the rod 73. The rearward extension is provided with a laterally extending arm 83 that alternately closes one of a pair of switches 84 and 86 when the plunger is moved to its rearward and forward limits. The switches 84 and 86 are appropriately mounted on a rearwardly projecting arm 87 that is held in fixed relation by the structural portion 77;

At the forward end of the assembly, the head portion 72 is carried in slidable relation therewith by a guide member 8-1 that is supported by the member 22. The guide member 81 is provided with a bushing 82 that maintains the head portion 72 in axial alignment as the latter is moved between its extended and retracted positions.

The expander mechanism carried on the forward end of the head portion 72 is adapted to radially-expand piston ring elements held by .the jaws. In its preferred form, the expander mechanism includes three cylindrical rollers 83, 8% and 91 that project axially forwardly from the front end of the head 72. As is shown in Fig. 7, the

I rollers are positioned with respect to each other to form a triangle that defines a circumscribing circle centered at the axis of the rings held by the jaws. The roller 91 is, in the present instance, an idler positioned at the bottom of the opening in the jaws, and serves merely to hold the rings down as the rollers 88 and 89 expand them. The rollers 88 and 89 are positioned in spaced relation above the central axis of the rings, on opposite sides thereof, and expand the rings bybeing moved into contact with the inner edges of the rings and thereafter moved to exert forces having components directed radially outwardly on the rings. In order that the rollers '88 and 89 may eifectively act as above described, theroller 88 is eccentrially mounted on an enlarged circular end 92 of a rotatable shaft 93, while the roller 89 is likewise ,mounted ona similar end 94 of a shaft 96. The shafts 93 and 96 are journaled in bushings, such as 95, carried in the head 72. The eccentricities between the rollers and their respective shaftsare both oriented so that the centers of the rollers are directly above the centers of their respective shafts before expanding the rings. By rotating the shafts so that the centers of the rollers 88 and 89 move outwardly from each other, the rollers expand the rings. Thereafter, by oppositely rotating the shafts, the rollers are returned to their initial positions so that the expanding plunger may be retracted.

In order to keep the rings centered as they are expanded, the shafts 93 and 96 are simultaneously rotated but in opposite directions. This is conveniently accomplished, in the present instance, by providing both shafts with gear teeth adjacent their inner ends 97. A reciprocable rack 98 is positioned between the shafts and is provided with teeth on its opposite sides that mesh with the teeth 97 on the two shafts. Thus, both shafts are rotated equal amounts in opposite directions by the same longitudinal movement of the rack. In the present instance movement of the rack 98 upwardly turns the rollers outwardly and expands the rings, and its movement downwardly turns the rollers inwardly to disengage the rings. The rack is driven by an appropriate fluid actuated piston in a cylinder 99.

The cylinder 99 is fixed to the underside of a flange 101 that extends rearwardly from the bottom of the member 22, beneath the guide member 81, the latter being mounted thereon as shown in Fig. 5. The cylinder 99 has its piston rod 102 extending upwardly therefrom and connected to an elongated member 103 which is, in turn, connected to the lower end of the rack 98, as by the universal connector 105. The piston rod 102 also extends downwardly below the cylinder and is provided with an adjustable stop assembly 104 on the lower end thereof for limiting the extent of upward movement of its piston and, hence, the rack 98.

For control purposes, the expander mechanism just described is provided with three switches 106, 107 and 108 (see Fig. 3) which are variously closed as the rollers 88 and 89 assume various positions. The three switches are appropriately mounted in fixed positions on the base. In the present instance the switch 106 is mounted below the cylinder 99 and is closed by the lower end of piston rod 102 when in its lowermost position, at which position the rollers define a circle of a diameter less than the inner diameter of an unexpanded piston ring. Theswitch 107 is closed by a laterally extending arm 109 carried by the assembly 104 when the piston rod 162 is in its uppermost position, and the rollers define a circle of a diameter equal to the inner diameter of a fully expanded ring. The switch 103 has a roller type plunger that is closed by a portion of the assembly 104 as .the piston rod 102 is being moved upwardly and the expanding rollers are at a position intermediate the two positions just described.

Thev expander plunger mechanism, as a whole, is provided with still other switches, such as switch 111, shown in Fig. 6, that is closed only when the plunger 26 is in retracted position and in response to the insertion of a piston into the expanded rings with the grooves of the piston in alignment with the rings. The switch 111 is mounted below the head portion 72. An elongated push rod 112 is carried by and extends longitudinally through the head portion 72 in slidable relation therewith. The forward end ofthe push rod 112 projects forwardly from the front end of the head portion 72 so that it will be pushed rearwardly by a piston inserted into the machine for loading. The rear end of the push rod 112 extends rearwardly beyond the rear end of the head portion.

The push rod 112 is spring loaded in the forward direction, as by spring 113. An elongated lever 114 extends upwardly from the plunger on the switch 111 to a point in alignment with the rear end of the push rod 112. The arm 114 is pivotally mounted intermediate its ends so that a rearward movement of the pushrod 112, when the head is in retracted position, causes the switch 111 to close.

'Before the plunger 26 can be retracted, after the rings have been expanded, means is provided for holding the rings in expanded condition. As will be more particularly described hereinafter, the piston ring elements are carried to the jaws and deposited in their respective slots therein in such fashion that their gaps are upward and in alignment. Expansion of the rings increases the width of the gaps a predetermined amount. By maintaining such width of gap, the rings are prevented from contracting, thus permitting the rollers to be returned to their initial position so that the plunger 26 may be retracted. In this machine, the spreading vane 27, previously mentioned, performs the function of maintaining the widened gaps of the expanded piston ring elements.

The spreading vane 27 is, in effect, a reciprocable abutment block that is dimensioned to fit within the gaps of the expanded piston ring elements without projecting radially inwardly into the central opening in the rings. The spreading vane 27 is carried on the forward end of an elongated member 116, as shown in Fig. 6. The member 116 is slidably disposed along the top of the head portion 72 so that the vane 27 may be projected through the opening 71 in the member 22 in alignment with the gap 31 between the upper ends of the jaws 23 and 24. The elongated member 116 is actuated between an extended position and a retracted position by a fluid actuated piston in a cylinder 117 secured to the portion 77 below the cylinder 76. A pair of levers 119, pivotally fixed intermediate their ends to the frame of the machine, and pairs of links 121 and 122 form the driving connection between the piston rod 118 of cylinder 117 and the member 116, astride the rod 73. As in the caseof the other fluid actuated cylinders, the stroke of the piston in cylinder 117 is adjustable by means of a stop assembly 123 carried on the rear end of the piston rod 118. For control purposes, a pair of switches 124 and 126 are provided for the spreading vane mechanism. The switch 124 is closed by the rear end of piston rod 118 when the spreading vane is in extended position and switch 126 is closed by the stop assembly 123 when the spreading vane is in retracted position.

As was hereinbefore stated, the piston ring elements are transferred by the machine from supplies thereof to the jaws to form complete sets. Each element of the set is delivered to its individual slot in the jaws in such fashion that the gaps in all the elements in the'set are in alignment with the gap 31 and hence the spreading vane 27. The apparatus for accomplishing the transfer of rings to the jaws includes guide structure that defines a plurality of channels in open communication with the slots in the jaws, and transfer means for moving the piston ring elements therethrough.

The guide structure serves not only to define conduits through which the ring elements are conveyed to the jaws but also is adapted to serve as guides for maintaining the ring elements in edgewise alignment with their respective slots in the jaws as they are moved thereto by the transfer means. The guide structure, in this machine, takes the form of a stack of rectangular plates spaced from each other and carried, in over lying relation, by the member 22. In the present instance, as shown in Fig. 6, a front plate 127, and four intermediate plates 128, 129, 131 and 132 are provided. The thickness of the intermediate plates and their relative spacing is such that the spaces, or channels, formed therebetween are utilized as the conduits through which the ring elements are moved, the spaces being coplanar with and of the same width as corresponding slots in the jaws. For convenience, these spaces are given reference numerals that correspond to those given the slots in the jaws, that is 37, 38', 39 and 4-1 respectively from front to rear.

The front plate 127 is imperforate except for appropriate bolt holes provided for securing the plate in position, and is cut out along its bottom edge, as at 133, (see Fig. 3), to provide clearance around the jaws 9 23 and 24, the expanding vane 27. Each of the intermediate plates is likewise cut out. A small cover plate 136 is fastened to the front plate 127 in front of the jaws. The cover plate 136 is providedwith a circular opening 137 that is alignedwith the jaws so that pistons may be inserted therethrough into the jaws. It is-also provided with a piston guide in the form of a trough 138 that projects forwardly from the bottom edge of the opening 137.

Rings are successively fed fiatwise to the spaces, or channels, 37, 38, 39 and 41 by mechanisms to be hereinfater described, from theback of the machine through appropriate circular openings in the member 22 and certain intermediate plates. In as much as there are four ring elementsper set to be loaded in the instant case, four such openings 139, 141, 14 2 and 143 are provided. The opening 139 is for'the lowermost rail on the. piston and hence extends through the member 22 and the plates 132, 131, 129 and 128, while the opening 143 isfor the upper rail and extends through the portion 22 and the plates 132, 131 and 129. The opening 141 is for the lower compression ring and extends through the portion 22 and the plates 132 and 131, while the opening 142 is for the top compression ring and extends only through the portion 22 and the plate 132. Thus, the back surfaces of the plates 127, 128, 129 and 131 serve as stops or abutrnents for positioning the piston ring elements in their respective channels preparatory to their being transferred to the jaws. The diameters of the openings 13?, 141, 142 and 143 are, of 'course, slightly larger than the diameters of the respective piston ring elements to be moved therethrough.

The transfer means for moving the ring elements to plunger26 and the spreading their respective positions in the jaws, sweeps them through the spaces between the plates. In the present instance four independently mounted transfer arms 144, 146, 147 and 148 are provided for this purpose and are mounted within the spaces, 37, 38, 39', and 41' respectively. EX- cept for certain dimensional characteristics, such as length and thickness, the arms are substantially alike and, the description of one should sutfice for all.

The arm 148, for instance, is a flat elongated member having a thickness slightlyless than the width of the space between the plates 12% and 129, that is, substantially the width of a piston ring rail. As is best shown in Fig. 3, one end of the arm is formed to have a concave arcuate profile, as at 149, that corresponds to the outer periphery of the unexpanded ring element it is to transfer. The arcuate profile is broken by a projecting lug or finger 151 that is dimensioned to snugly fit in the gap in the piston ring element. The finger 151 is positioned so that the gap will be held fixed relative to the arm as it is swept to the jaws. At its other end, the arm 143 is fixed to a shaft 152 that projects rearwardly through the plates and the member 22. The centerof the shaft 152 is vertically aligned with the center of the opening 139 and is horizontally aligned with the center of the opening between the jaws, and the distance between 'the center of the shaft 152 from the center of the opening 139 is equal to the distance between the shaft 152 and the center of the opening between the jaws. It is thus seen that after engaging a ring element at the opening 143, upon the arm 14$ sweeping through an arc of 90 clockwise as viewed from the front of the machine, the ring element will be moved thereby into the slot 38 in the jaws. Also, the gap in the ring, held by the lug 151, will be properly oriented, in this instance in alignment with the gap 31 between the jaws. The arms 144, 146 and 147 are similarly formed with concave arcuate profiles and lugs and are similarly mounted on rearwardly.

positioned in the slots 37', 39', and 41 respectively,

for arms.

10 and their respective shafts are arranged relative to the openings 139, 141 and 142 respectively and center of the ring positions in the jaws in accordance with the above/outlined relationship. Thus, upon the arms 144, 146 and 147 all sweeping through arcs of their respective ring elements will all be deposited into the top of the jaws in their respective slots with their gaps in alignment with the gap 31. It is of course clear from Fig. 3 that the arms 144 and 146 are positioned on the opposite side of the jaws from the arms 148 and 147 and, therefore, move their rings in a counterclockwise direction toward the jaws.

In order to simplify the driving mechanism for the arms, the centers of shafts 152, 153, 154 and 156 are aligned along a horizontal line through the center of the ring positions in the jaws. In the illustrated machine, the shafts 152, 153, 154 and 156 are journaledrespectively in bushings mounted in sleeves 157, 158, 159 and 161, (see Fig. 8) carried by the member 22. Rearwardly from the sleeves, pinions 162, 163-, 164 and 166 all of the same size are mounted on the respective shafts 152, 153, 154- 'and 156. An interengaging idler gear 167 is disposed between the pinions 162 and 163, while another idler gear 168 is similarlyinterposed between the pinions 164 and 166 to form two sets of pinions on the respective sides of the jaws. Thus, each set of pinions, and hence the arms connected thereto, will rotate in unison in the same direction and by an equal amount, upon rotation of one of the pinions in each set, the pinions in one set being rotated oppositely to those in the other set.

Rotation of the sets of pinions is. effected by reciprocable racks. Thus, as is shown in Fig. 5, a vertically extending rack 169 engages the pinion 162. The rack 169 is connected to the piston rod 171 of a fluid actuated piston in a cylinder 172 mounted on the flange 101. The rack 169 engages the pinion 162 so that with the piston of the cylinder 172 in its lowermost position, the arms 144 and 146 are substantially upright, asseen in Fig. 3, in ringpick-up position. As the piston is actuated upwardly, the rack drives the pinion 162 clockwise as viewed from the front of the machine. Through the idlergear 167, this action also drives the pinion 163 clockwise in unison with pinion 162. This causes transfer arms 148 and 147 to sweep through a clockwise are such that the piston ring elements carried thereby will be transferred to and deposited in their respective slots in the jaws. Similarly, the pinion166 is driven by a rack 173 which is in turn actuated by the piston rod 175 of a fluid actuated piston in a cylinder 174. As in the case of the other fluid cylinders previously described, the strokes of the pistons in the cylinders 172 and 174 are adjustable by means of suitable stop structures 176 and 177 on the lower ends of piston rods 171 and 175 respectively.

. For control purposes, four switches 178, 179, 181 and 182 are provided to operate in conjunction with the trans- These switches are appropriately mounted in fixed relation on the base. The switch 179 is mounted so that it will be closed by the lower end of the piston rod 171 and the switch 182 is mounted so that it will be closed by the lower end of the piston rod 175 when their respective transfer arms are in ring-pick-up position. The switch 178 is mounted so that it will be closed by a laterally projecting arm 1S3 carried on the end of piston rod 171 and the switch 181 is mounted so thatit will be closed by another laterally projecting arm 134 carried on the end of piston rod 175 when their respective transfer arms have moved fully to the jaws.

The machine also includes means for storing supplies of the ring elements and for conveying themes needed to the transfer arms. In general, this means includes a plurality of storage units for holding stacks of piston ring in proper orientation to be'received bythe transfer arms.

More specifically, the instant machine is provided with four cylindrical storage structures, shown generally at 186, 187, 188 and 189 (see Fig. that project rearwardly from the member 22, perpendicular to the plane thereof and in axial alignment with the openings 143, 142, 141 and 139 respectively. The cylindrical storage structures are dimensioned so that they will support stacks of piston ring elements, yet will permit them to be slidably moved therealong. Each storage structure is provided with a ram mechanism for moving its stack of ring elements. In general all of these structures and their ram mechanisms are alike, their differences being dictated by the differences in the ring elements they are adapted to support.

All of the storage structures are preferably in the form of tubes having axial bores, such as is indicated at 191 in Fig. 5 and at least a portion of each has an outer diameter slightly less than the inner diameter of the ring element carried thereby. In each case the portions of the storage structures nearest the member 22 are adapted to carry their respective ring elements on the external surface thereof. Each of the storage structures is provided with a slot through the wall thereof such as 192, that extends longitudinally the length of the structure. The

storage structures are mounted so that their slots, such as 192, are in alignment with the lugs on the respective transfer arms that they supply. The storage structures are rigidly supported through these radial slots by elongated members, such as 193. Plate-like portions 194 on the elongated members 193 project into the slots and are rigidly secured therein, the members 193 being rigidly fastened to the base. As is shown in Fig. 4, each storage structure is supported by a pair of members 193, one in the front portion and one in the rear portion of each of the slots. The adjacent ends of each pair of such elongated members 193 are spaced from each other to provide clearance in the slots for gears, which will be hereinafter described. The thickness of the various plate-like portions 194 are approximately equal to the width of the gaps in the various piston ring elements carried on the storage structures. Thus, these portions, in addition to supporting the tubes, are adapted to hold the gaps of all rings properly oriented until discharged therefrom to the transfer arms.

The forward end of each of'the tubes is externally flared, as shown at 195, to expand therings slightly as they are discharged into their respective channels. As will be explained hereinafter, the rams apply pressure to move the ring elements to their respective transfer anns only intermittently. The flared end 195, therefore, prevents a ring, once forced from the end of structure, from moving back onto the end thereof when the rams are not pushing forwardly. In the present machine, each of the storage structures includesa tapered end piece, such as 196 (see Fig. 4), that is secured at the forward end thereof to provide the flared end 195. Furthermore, the tapered end pieces of the structures, just described, terminate just short of the spaces between the plates 128, etc., into which the piston ring elements are to be deposited, to provide clearance between the forward ends of the end pieces and their respective transfer arms. V

The storage structures 187 and 188, in the present instance, carry the compression rings and are each a single continuous tube. Each tube, in its rear part, is provided with a pair of opposing radial slots 197 that extend longitudinally forwardly from the rear end thereof. The slots 197 act asguides for connecting Lhgs on part of the ram mechanism, described hereinafter; and are longitudinally dimensioned to limit ram travel. In this case the outer diameter of the entire tube is slightly. less than the inner diameter of the'compression rings carried thereby. Thus, compression rings are loaded thereon by stacking them over the rear end of the tubes.

The structures 186 and 189 carry the two oil ring rails,

and, because of special considerations dictated by the characteristics of the rails, as was discussed in the early paragraphs hereof, the structures are modified somewhat from the basic pattern described in connection with the structures 187 and 188. Considering the structure 186 (since the structures 186 and 189 are similar), this structure is, basically, a pair of tubes 198 and 199 arranged in end-to-end relation with their longitudinal axes in alignment. The tube 199 corresponds, generally to the tubes of the structures 187 and 188, having an outer diameter less than the inner diameter of the rails to be carried thereby. The tube 199 is the forward section of the structure, the rings being supported on the exterior thereof as above described. The tube 198 is the rear portion of the structure and, in this case, has an inner diameter larger than the outer diameter of the rail elements. The rail elements are loaded into the rear of the tube 198 and are supported by the inner surface thereof. The forward end of the tube 198 telescopes over the rear end of the tube 199 to provide continuous support for the rings as they emerge from the tube 198 over the end of the tube 199. As an aid to the transference of the ring elements from the tube 198 to the tube 199, the rear end of the latter is provided with a sleeve portion 201 that has its rear'end inwardly tapered as at 202 and which has an outer diameter slightly larger than the tube 199. This sleeve portion expands the rails somewhat to provide greater gap opening. The sleeve portion 201 extends longitudinally sufficiently to bridge the gap between the adjacent ends of the two members 193. The plate 194 of the rearmost memher 193 for this structure projects inwardly into the bore of the tube 198 and serves as a slot orienting guide.

The rams for advancing the ring elements along their respective storage structures, and including the actuating mechanisms therefor, are all substantially the same. They differ only in the structural details of their ring pusher elements.

The ram for the storage structure 186 is most completely shown in Fig. 4. In the present instance, the ram for the storage structure 186 comprises an elongated longitudinally movable rod 203 that is disposed in the bore of the tubes 198 and 199. The rod 203 is sufficiently long to extend from the rear end of the tube 198 to a point just beyond the front end of the gap between the adjacent ends of the members 193. The rod 203 has a longitudinally extending toothed rack portion 204 that faces outwardly toward the plates 193. On the rear end of the rod 203 is removably mounted a circular pusher element 206 which is the piston ring element engaging portion of the ram. Pusher element 206 also serves the additional function of maintaining the rear end of the rod 203 in axial alignment with the bore of the storage structure 196. The forward end of the rod 203 is maintained in axial alignment by a pair of bushings 207 carried in the sleeve portion 201. Forward movement of the pusher element 206 is limited by abutment structure on the rear end of the sleeve portion 201, and is shown at 205.

The pusher element 206 is a piston-like element, having an outer diameter slightly less than the inner diameter of the tube 198, and is longitudinally slotted along the side facing the plates 193 as at 208, to provide clearance therefor. The forward edge of the pusher element 206 is formed to present a flat annular pushing surface 209 to the ring elements positioned within the tube 198. The pusher element 206 is held on the rear end of the rod 203 by a collar member 211. The collar member 211 is made to be freely manually removable from the end of the rod 203 so that the pusher element 206 may be quickly detached when loading of additional stacks of piston ring elements on the storage structure is required. The collar member 211 is in this instance a horseshoe-shaped element that is dimensioned to straddle a portion 210 of reduced section of the rod 203 immediately to the rear of the pusher element as shown in Fig. 4.

l The rams are driven by fluid actuated pistons and cylchine.

. is inders similar to those previously discussed. For the structure 18 6, the piston of a cylinder 212 drives the rod 203, and is mounted on the frame of the machine with its longitudinal axis generally parallel to that of the structure 186, the fluid cylinder 212 being positioned further toward the outside of the machine thanits storage structure 186. The fluid cylinder 212 has its piston rod 213 extending rearwardly and connected to a rearwardly extending rack 214, the latter being longitudinally movable in response .to actuation of the cylinder 212. a The teeth on the rack 214 face inwardly toward the teeth on the rack 204 and .the rack 214 is slidably supported by a guide 216 that is rigidly mounted on the frame of the machine.

For driving the ram of the storage structure 186, the rack 204 and the rack 214 are interconnected by appropriate gearing which, in this instance, does not change the direction of movement but multiplies the amount of movement imparted. Thus, an idler-gear 217 is mounted on the frame of the machine in engagement with the rack 214. The idler gear 217 also engages a pinion 218 rigid with a second idler gear 219, the idler gear 219 being also rotatably mounted on the frame of the machine and in driving engagement with'the rack 204. The gear 219 is relatively thin to extend through the gap in the piston ring elements carried by the structure, in order to engage the rack 204.

It is thus seen, from an examination of Fig. 4, that as the rack 214 is pulled forwardly by the fluid cylinder 212, the gear 217 will be rotated counterclockwise, the gear 219, through the medium of the pinion portion 218, will be rotated a greateramount clockwise, and the rack 204 will be drawn forwardly to advance the ring elements along the storage structure. This action is accomplished only intermittently, when the transfer arms are in ring pick-up position.

The rams forthe other storage structures are similarly actuated, and all are operated in unison so that the various ring elements are delivered in sets to the transfer arms.

Except for its being oriented to be driven from the left side of the machine rather than the right as seen in Fig. 4, the ram for the storage structure 189 and its driving mechanism is similar to that just described. With respect to the rams for carrying the compression rings along the storage structures 187 and 188, the only significant difference that exists between them and that just described, resides in their ring pusher elements. For the structure 187, a pusher element 221 is provided for pushing the piston ring elements along the outer surface of the tube of this structure. The pusher element 221 comprises an outer sleeve-like pusher portion 222 connected to a central hub portion 223 by a pair of lugs that project inwardly through the slots 197. Thus, it is seen that the length of the slots 197 determines the maximum forward movement of the pusher element 221.

In addition to the switches heretofore mentioned, the machine is provided with control means adapted to initiate that portion of the cycle "of operation that is preparatory to the loading ring elements on a piston. In the present instance this means comprises a photo-electric eye circuit. Thelight beam source and photo-electric cell unit, one being shown at 224 (see Figs. 1 and 2) and the other at 226, are positioned on opposite sides of the piston loading position so that their beam of light will be interrupted by a piston inserted into ring receiving position in the ma- Upon removal of the piston, after it has been loaded, the beam of light is reestablished and it energizes the photo-electric cell to initiate a new cycle of operation.

In general, the major portion of the control components for the machine are located on the control panel portion 19, and comprises electric solenoids, electric relays and fluid control valves. The various switches hereinbefore mentioned and the photo-electric eye device together with 5 the various electric circuits and fluid conduits, comprise control panel portion 1?. These control elements are .of switch 86 results in two things.

well known in the art and are conventionally employed in the instant machine to carry out the cycle of operation hereinafter described. Detailed description of these various control elements and their circuits is therefore believed to be unnecessary.

The cycle of operation of the machine is initiated, as mentioned above, upon reestablishing the beam of light between the light source and the photo-electric cell, as by the withdrawal of a piston previously loaded. The photoelectric cell when energized effects supply of fluid pressure to the cylinder 42 and 52, whereby the jaws 23 and 24 are moved to closed position. Closing of the jaws causes switches 34 and 36 to be closed whereby fluid pressure is supplied to thecylinders 172 and 174. It is assumed that piston ring elements have been previously deposited on the four transfer arms 144, 146, 147 and 148, as will be described later in the description of the cycle. Actuation of the cylinders 172 and 174 causes the four transfer arms to sweep their respective piston ring elements to and deposit them in their respective slots in the jaws.

Upon the transfer arms reaching the limit of their inward sweep, switches 178 and 181 are closed. This action results in supplying fluid pressure to the cylinder '76 so that the expanding plunger 26 is moved forward into ring expanding position. This in turn causes the switch 86 to be closed when the expanding plunger has reached the end of its forward movement. The closing First, it causes fluid pressure to be supplied to the cylinder 99 to effect rotation of the rollers 83 and 89 for expanding the ring elements. Second, it causes fluid pressure to be supplied to the secondary cylinders 52 and 64 to open the jaws 23 and 24 to their intermediate position.

As the rollers 88 and 89 are rotated by the action of the cylinder 99, and before the piston of the latter has reached its limit of upward movement, the switch 108 is closed. The closure of switch 108 causes the cylinders 172 and 174 to return the transferarms 144, 146, 147 and 148 to their ring pick-01f positions at the openings 139, 141, 142 and 143, respectively, in readiness to receive the next set of ring elements from the storage structures.

When the cylinder 99 has fully rotated the rollers 83 and 89 to fully expand the set of piston ring elements, switch 1%! is closed thereby, and when the transfer arms have been returned to ring pick-off position by the cylinders 172 and 174, switches 179 and 182 respectively are closed thereby. In response to the closure of these three switches, the piston in the cylinder 117 is actuated rearwardly to effect forward movement of the spreading vane 27. Upon reaching its rearward limit of travel, piston rod 118 of cylinder 117 closes switch 124, indicating that the spreading vane 27 is projected forwardly to hold the piston ring elements in expanded condition and allow the expanding plunger to be withdrawn. The closure of switch 124 results in actuation of the piston of cylinder 99 so that the rollers 88 and 89 are moved inwardly from the edges of the piston ring elements. When the rollers have been returned, switch 106 is closed and the piston of cylinder 76'is actuated to withdraw the expanding plunger.

With the expanding plunger withdrawn, the machine is ready to load a set of rings on a piston and further operation stops until a piston is manually inserted into ring receiving position to signal the machine operator that this phase of the cycle has been completed, a suitable signal light 227, positioned on the front of the machine, operates in response to the closing of the switch 84. Of course, because the preceding steps are all accomplished automatically in sequence, only an interval of a few seconds from the withdrawal of the preceding piston is required to complete this portion of the cycle.

The final portion of the operating cycle is begun upon the insertion of a piston into the loading opening defined by the jaws and the expanded piston ring elements.

.A piston inserted fully therein depresses .the push rod 112 and thus closes the switch 111. The closing of the switch 111 effects actuation of the pistons in the various feedram cylinders so that a single ring element is forced from the forward end of each of the supply structure into the. transfer arms in readiness for the next cycle of operation.

At the same time, the closure of switch 111 also causes actuation of the piston in the spreading vane cylinder 117 to withdraw the spreading vane 27. The withdrawal of the spreading vane allows the rings to snap into their respective positions in the grooves on the piston, distortion of the rings being avoided by reason of their being supported by the jaws. Through a time delay mechanism in the control circuit, acting in conjunction with the switch 126, which switch is closed when the spreading Vane has been withdrawn, the cylinders 42 and 59 are actuated to fully open the jaws Band 24 so that the piston with the piston ring elements mounted thereon may be withdrawn from themachine.

The cycle is concluded in response to the closing of the switch 68, which causes the feed rams to back off and relieve the pressure on the stacks of ring elements carried by the storage structures. The machine is now in readiness to repeat the cycle upon the removal of the loaded piston.

It is thus seen that a novel machine is provided, that automatically loads sets of piston rings on pistons as the latter are fed to the machine by an operator. The machine automatically picks up a full set of rings and resets itself for a succeeding loading operation after withdrawal of each loaded piston.

Although the invention has been described in connection with a certain specific structural embodiment, it is to be understood that various modifications and alternative structures may be resorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A piston loading machine comprising a base, releasable means on said base, said releasable means being adapted to collect and to hold in predetermined axially spaced relation one or more piston ring elements, said releasable means including a pair of rollers movable to expand said elements for insertion of a piston within said elements with the grooves of the piston aligned with said elements, storage structure carried by said base and adapted to hold a quantity of the piston ring elements to be loaded by the machine, one or more pivotally mounted transfer arms for moving the piston ring elements from said storage structure to said releasable means, mechanism for actuating both of said means, and control means for controlling the operation of said mechanism in a predetermined sequence.

, 2. A piston loading machine according to claim 1, in which each of said arms has an arcuate ring element engaging surface, and a lug extending from said surface engageable in the gap of its associated ring element for holding thering element properly oriented.

3. A piston loading machine according to claim 1, in which each of said arms is rigidly connected to a pinion and the pinions of two of said arms are connected by an idler gear, and in whicha power operated rack is in meshing relation with one of said two pinions for swinging the associated arms.

4. A piston loading machine according to claim 1, in which said storage structure comprises a plurality of storage devices, each device comprising a tubular member for receiving a plurality of ring elements thereon, and ram means for intermittently pushing the ring elements along said tubular member to said moving means, said tubular member having a flared end adjacent said moving means to slightly expand the ring elements when the latter are pushed thereover, whereby the ring elements are prevented from reengaging over the tubular member 16 and are maintained in position for movement by said transfer arms.

5. A piston loading machine according to claim 1, having means for guiding the piston ring elements dur ing their movementfrom said storagestructure to said releasable means by said transfer arms, said guiding means comprising a plurality of spaced plates with the ring elements adapted to be fed into the respective spaces between said plates, said transfer arms being located in said spaces for moving the ring elements therein.

6. A piston loading machine according to claim 5, in which said transfer arms are positioned in the respective spaces between the plates and swingable in said spaces from said storage structure to said releasable means.

7. A piston loading machine according to claim 1, in which said releasable means includes a pair of jaws having a plurality of ring element receiving slots therein, means for guiding the ring elements from said storage structure to said jaws, said guiding means comprising a stack of spaced plates having an aperture to receive said jaws and having the spaces therebetwee n aligned with the slots in said jaws, said storage structure being adapted to feed ring elements into the respective spaces between said plates, and said transfer arms being located in said spaces for moving the ring elements therein to said slots.

8. A piston loading machine according to claim 7, in which said storage structure is located adjacent one face of said stack, and the respective plates having different numbers of openings therethrough for the passage of ring elements from said storage structure to the respective spaces therebetween the plates.

9. A piston loading machine according to claim 1, in whichsaid storage structure comprises a plurality of storage devices mounted on the respective sides of said releasable means, and in which said transfer arms are swingable from the respective storage devices to said releasable means to axially align the ring elements therein.

10. A piston loading machine according to claim 9, in which each of said arms is provided with means for holding the gap in its associated ring' element in a predetermined position to align the gaps of all of the ring elements when the latter are moved into said releasable means.

11. A piston loading machine according to claim 1, in which said storage structure comprises a plurality of storage devices, each comprising a tubular member for receiving a plurality of ring elements thereon, and ram means for intermittently pushing the ring elements along said tubular member toward said transfer arms.

12. A piston loading machine according to claim 11, in which each of said tubular members is longitudinally slotted, and an elongated plate-like member extends into i the slot in each of said tubular members to hold the gaps in the ring elements on said tubular member aligned.

13. A piston loading machine according to claim 11, in which each of said tubular members is provided with means at its rear end to receive a stack of ring elements aligned with the ring elements on said tubular member, and saidram means comprises a pusher portion engaging said' stack of ring elements, and an elongated rack connected to said pusher element and extending into said tubular member, said tubular member being longitudinally slotted, and drive gearing extending through the slot in the tubular member and meshing with said rack.

14. A' piston loading machine comprising a base, movable jaw means on said base, said jaw means being adapted to collect one or more piston ring elements and hold the same in predetermined axially spaced relation, means carried by said base and cooperating with said jaw means for expanding and releasably holding the piston ring elements in position to be mounted on pistons, storage structure carried by said base and adapted to hold a quantity of the piston ring elements to be loaded by the machine, means for moving the piston ring elements from said storage means to said jaw means, mech- '17 anisms for actuating each of the foregoing means, and control means for controlling the operation of said mechanisms in accordance with a predetermined sequence.v

15. A piston loading machine comprising a base, a pair of relatively movable jaws on said base, said jaws being adapted to receive one or more piston ring elements and to hold the same in predetermined axially spaced relation, means carried by said base and cooperating with said jaws for expanding said piston ring elements, means for releasably holding the piston ring elements in expanded condition for mounting on pistons, storage structure carried by said base and adapted to hold a quantity of the piston ring elements to be loaded by the machine, guide structure interconnecting said storage structure and said jaws, means cooperating with said storage structure for feeding said piston ring elements to said guide structure, transfer means cooperating with said guide structure for transferring the piston ring elements edgewise and in predetermined spaced relation into said jaws, mechanisms for actuating each of the foregoing means, and control means for controlling the operation of said mechanisms in accordance with a predetermined sequence.

16. Structure according to claim 15, in which said holding means comprises a vane insertable into the gaps of the ring elements when the latter are expanded by said expanding means.

17.Structure according to claim 15, in which said jaws are movable from a closed position slightly less than the diameter of the piston for receiving said ring elements, to an intermediate position to permit the piston to be inserted therebetween, and thento an open position to free the jaws from the ring elements when the latter are closed on the piston.

18. Structure according to claim 15, in which said expanding means is movable to a position between the jaws for expanding the ring elements, and said holding means is movable into the gaps of the expanded ring ele' ments for holding the ring elements expanded, and said expanding means is thereafter withdrawable to permit the insertion of a piston between the jaws.

19. Structure according to claim 15, in which said expanding means comprises a pair of members movable between said jaws and engageable with the inner periphery of the ring elements on opposite sides of the gap therein and movable outwardly to expand the ring elements.

20. Structure according to claim 19, in which said pair of members comprises a pair of eccentrically mounted rollers. V

21. Structure according to claim 15, in which said expanding means comprises a plunger carrying a pair of eccentrically mounted rollers and is movable to position the rollers between the jaws for engaging the inner periphery of the ring elements, said rollers being rotatable to expand the latter.

22. Structure according to claim 21, including mechanism for reciprocating said plunger, mechanism for rotating said rollers and extending into said plunger, said holding means being slidably supported by said plunger, and mechanism for shifting said holding means into and out of engagement with the ring elements.

References Cited in the file of this patent UNITED STATES PATENTS 1,537,773 Johnson May 12, 1925 1,712,907 Stenhouse May 14, 1929 1,755,044 Bailey Apr. 15, 1930 1,764,146 Bramberry June 17, '1930 1,852,613 Jessen Apr. 5, 1932 1,983,965 Berkman Dec. 11, 1934 1,993,754 Smith Mar. 12, 1935 2,195,216 Kulp Mar. 26, 1940 2,792,625 Hofiman May 21, 1957 

